** Express Scripts Holding Co and CVS Health Corp said they had dropped Philidor Rx, a specialty pharmacy associated with Valeant, from their networks

** Valeant’s shares tumbled last week after influential short-seller Citron Research said the company was using specialty pharmacies to inflate revenue

** Valeant has vigorously defended the allegations; Company’s largest shareholder says allegations are false and that there is no legal case preventing ties to a specialty pharmacy

** Valeant’s U.S. shares have lost more than half their value since mid-September after Hillary Clinton called to attention the issue of pharmaceutical “price gouging”; U.S. prosecutors are investigating the company over its drug pricing